The field of this disclosure relates generally to gas turbines and, more particularly, to gas turbine diffusers.
At least some known gas turbines include a compressor, a combustor, and a turbine. Ambient air flows into the compressor and is compressed. Compressed air is then discharged into the combustor wherein the compressed air is mixed with fuel and ignited to generate combustion gases. The combustion gases are channeled from the combustor through the turbine, thereby driving the turbine which, in turn, may power an electrical generator coupled to the turbine.
A diffuser is often coupled downstream from the turbine to facilitate recovering static pressure and increasing the operating efficiency of the gas turbine. However, at least some known diffusers include support struts that extend across a flow path of the diffuser. Such support struts at least partially obstruct and may disrupt gas flow through the diffuser. For example, when the gas turbine is operating in partial load conditions, combustion gases discharged from the turbine may flow over the support struts at a greater angle of incidence (i.e., the combustion gases may be discharged from the turbine with a greater swirling action) than may occur when the gas turbine is operating during base load conditions. The increased swirling may cause the flow of combustion gases over the struts to separate, thus reducing the static pressure recovery capability of the diffuser. It would be useful, therefore, to provide a diffuser that facilitates causing less flow separation over the struts when the gas turbine is operating in partial load conditions.